Provided are an external preparation for skin and a wrinkle-reducing agent exhibiting an excellent effect of reducing wrinkles that develop particularly in an exposed site along with aging, and having high safety. The external preparation for skin and the wrinkle-reducing agent each contain an alkyl thioglycoside represented by the general formula (1) : G-SR 1 (1) (in the formula: G represents a sugar R 1 represents an alkyl group having 10 to 18 carbon atoms and G and an SR 1 group are bonded to each other via a ²-glycosidic bond).
